Jet pronged digging heads



p 22. 1 A. H. GOETT 2,905,443

JET PRONGED DIGGING HEADS Filed'Jan. 23, 1956 INVENTOR. AE/VOLD H. 60577 BY WWKM United States Patent JET PRONGED DIGGING HEADS Arnold H. Goett, Seattle, Wash.

Application January 23, '1956, Serial No. 560,588

2 Claims. (Cl. 255-61) The present invention relates to a digging head of the jet type to be supported on the end of a pipe and driven through the ground for the purpose of laying the pipe without the necessity of digging a trench in which to lay it.

An object of the present invention is to provide a digging head affording a combined hydraulic jetting and digging or ground-loosening action, so that the jet will dislodge the earth ahead of the head to enable it to progress rapidly through the ground.

A more specific object is to provide such a head which, by appropriate movement of a pipe on which it is mounted, can be reciprocated and/or rotated to loosen the dirt ahead of it effectively and which will clear a burrow through which the remainder of the head may pass readily.

Another object is to provide such a digging head provided with jets to keep the cavity between the dirt loosening prongs clear so as to maintain the digging or dirt loosening effectiveness of the prongs.

It is also an object to provide such a digging head which will have dirt loosening prongs of a character that will tend to displace the dirt from their path and which preferably are reasonably sharp to facilitate their digging action. Such prongs also may be of such shape and arranged so that they can be resharpened easily as they are dulled by use.

An additional object is to arrange jet passages through the digging head so as to clear the cavities between adjacent prongs most eificiently and thus maintain the digging or dirt loosening effectiveness of theprongs.

The foregoing objects can be accomplished by a digging head of substantially cylindrical shape having a pipe receiving socket in one end and a plurality of digging prongs projecting generally axially from the opposite end. Such prongs are spaced radially and circumferentially, each prong being of a greater extent radially than circumferentially, and such prongs'diverging from their root ends to their tips to a spread greater than the maximum width of the socket end of the body. Jet bores extend longitudinally through the body, having one end opening into the pipe-receiving socket and including a principal central bore having its other end opening at the center of the cluster of prongs and side bores which diverge from the pipe receiving socket and open respectively in circumferentially spaced positions between the prongs.

Figure l is a top perspective view of the jet pronged digging head mounted on a pipe.

Figure 2 is a longitudinal sectional view through the digging head taken on line 2-2 of Figure 4, and Figure 3 is a longitudinal sectional view through the digging head taken on line 3-3 of Figure 4. Figure 4 is a front view of the digging head.

Figure 5 is a longitudinal sectional view through a digging head of a different form, taken on line 5-5 of Figure 6, and Figure 6 is a front view of such modified form of digging head.

In order to burrow most effectively for laying a pipe it is preferred to use a combination of mechanical and hydraulic actions. Such actions in combination are produced by the digging head 1 shown in Figure 1 as being mounted on the end of a pipe P to be installed in the burrow. Exposed beyond the open end of the burrow is a T T screwed onto the end of pipe P, to the side leg of which is connected the water pipe W. A nipple N is connected to the leg of the T opposite that to which the pipe P is connected, and a second T T2 has its side leg connected to the other end of the nipple N. The other legs of the T T2 are closed by plugs.

The digging head includes a body 1 preferably of substantially cylindrical shape, having a threaded socket 2 in one end for receiving the threaded end of pipe P. From the opposite end of the body prongs 3 project, as shown in Figures 1, 2 and 3. These prongs project generally axially from the body and are spaced both radially and circumferentially. As shown in Figure 4, each prong is of greater extent radially than circumferentially. The prongs diverge somewhat from the body so that the total spread of the cluster of prongs adjacent to their tips is greater than the maximum width of the socket end of the body.

While the number of prongs provided may difier, there should not be so many of them as to restrict too greatly the circumferential spacing between the prongs. The tip of each prong should be reasonably sharp, preferably in the form of a ridge, and it is desirable for such ridge to be inclined relative to a plane perpendicular to the axis of the head so that the ends of such ridges farther from the heads axis are located farther from the body 1 than the other ends of such ridges, as shown in Figure 2. Also the prongs may taper somewhat in a direction away from the body throughout their entire length, as shown in Figure 2.

While the prongs 3 can be used to loosen dirt in the end of a burrow by probing with them, the progress of digging the burrow is greatly expedited by sluicing away from in front of the digging head dirt loosened by the prongs. Such sluicing action is accomplished by pro jecting water from the head through jet bores. In the digging head shown in Figures 1 to 4, inclusive, the principal jet bore extends centrally through the head, having its feed end extending through a stem 4, located concentrically within the pipe-receiving socket 2. The discharge end 5 of the bore opens at the center of the cluster of prongs 3 adjacent to their root ends.

In addition to the central jetlbore side jet bores 6' are provided, each having one end opening into the pipereceiving socket 2. These side bores diverge from their feed ends to their discharge ends, which open respectively in the valleys between adjacent prongs 3. Thus it is preferred to have at least as many side jet bores 6 as there are prongs 3 and to have the side jet bores and prongs located in alternating arrangement, as shown best in Figure 4. Also the side bores may be smaller than the central bore, as shown. If dirt should get into the head, either through the side bores or otherwise, and be packed in the end of the cavity in the head by the water, the stem 4 will insure that at least the central bore will not be clogged.

In operation water will be supplied through the supply pipe W to the pipe P being laid. The water will flow from this pipe through the digging head and will.

be projected as high pressure sluicing jets from bores 5 and 6. The entire pipe P may be reciprocated lengthwise, as well as being rocked or rotated through part of a turn, by manual manipulation of the pipe to work Patented Sept. 22, 1959 the prongs 3 into the dirt at the end of the burrow. however, the method of using the digging head shown As the dirt is loosened by the prongs, it will be sluiccd in Figures 5 and 6 willbe similar to that erasing" the out of the way of the prongs. 3 through the clearance digging head shown in Figures 1 to 4, inclusive, and the betweenthe wall ofthe burrow and the body..1 by the? operations will be generally comparable.

water from the jets, so as to produce an-flicient:diggin I claim as my invention:

operationlf. theadirt..atfthe.end.of thelburrcfwshould l. A digging head comprising a hollow body, pipe be a uitehard or if an obstruction shouldbe encountered; connecting means on one end of said body for connecadditionalpressure can be applied lengthwise to. the:pip tion to a pipe communicatihg'with the hollow of said LP by using a bar-B topry on theend of the pipe assembody, and a cluster ofsprongs ;projectingrgenerally axibliformed-bythe-T T2. n l ally from the opposite end of said body and spaced The jet ofwaterprojected-from.the discharge end l circumferentially t'oforrrrvalleys between circumferenof .thecentral bore will keep the central spacebetween tially adjacent prongssandr radially to form a cavity. centhe prongsfi clear of dirt,-.whichwould: tend to ipack trally between said prongs, the axial length of each'of insit ,;:and'the side jets projected from .bores 6 in the A: said prongs being at least a plurality -oftimes as great valleys between the prdngs.will. prevent dirt from pack :1 as its circumferential extent, the outer edges of said ing in such valleys. Consequentlygthe is prevent'edl prongs having their root ends substantially flush with from packing around-the sharpened ends of theprongs ,M the sides of said body and diverging from said body 3, :sothat tl 1eirdirt' looseningaction willanotbe imtoward their etipge the tips ofesaidprongs beingoppo; pairedi Thedirt expelled from the spaces between the sitely beveled to form-substantially sharp ridges extendteeth backward throughlhe. clearance between thebur- 2O ing; radially ofesaidbody and inclined relative to'a plane row wa'll and the bodyl will be packed sufficientlyvby disposedrperpendicular to theaxis-ofsaid body, .and a r;

thelsluicihg actiontof make room for formation ofthe i jet bore extending through said body havingvits outers, burrow to receive the pipe. The inclined crests of the end opening :in said 'central cavity and its inner. end

prongs-3 will :tend .to wedgethedirt intothe space at openingintotheghollow ofsaid body.

thecenterof the cluster of prongs-sothatit will be sub 2. e-A digging head comprising a hollow body, ipip'erjected to theimpachoi the largecenter'jet more effec onne irig means on-one rend -of said body for connec y;

tively... A g tion to a pipe communicating with. the hollow ofsaidfl An alternativety e of digging head is shown in-Fig'a ya nd-a 1== f=p ongs--p i e ly ures 5 and 6. This digging head includes thesametype. ally frorn the opposite end ..of ;-said' bodyand spaced fab d l, having. i iit the .pipeereceiving cavity 2 and circumferentially to form-walleye between circumferene central jetsterrr 4, as discussed in .connection with the yi i n P '0ng the axial length of each of said-e previous modification and the manner in Whichthis'dige; P PE e sat least-a P -l Y times as great ging uheadflfs t d d. i u d are th same a thlos circumferential extent, the outer edges of 'saidrprongs already des cribed. Similarly, the central bore has a dising their -root.ends snbSt fi Y flush with thei'sides chaiigeendi opening at the center of the-cluster-of Q NS I DOdYZaMdiverging-from.said body toward theiree diggingprongs, and the side "jet-bores 6 extending from. p g thetips of. said .prpngsebeingaoppositelybeveled thezsocketz diverge in the manner previouslydescribed e to form substantially 3 'PI g ra i llyob t0 .bpen-in the valleys between the-dirt loosening prongs -bi y a i c r lative tO-a plane disposedper 'rlig rinei l difierence of the'digging-head shown p n ie e of saidibodyrand a p io inLFiguIesS and .6 over that shown in Figures 1 to-4 l -l l Said dy' their Ollierfl resides, therefore, in the shape of the individual' dirt. d p i fi g j Said l' fi yr l"b looseningprongsfi. Each of these prongs 7 is of conl ;-P a ends pe g-in siderably greater radial extent than that of; each of the--- theehollow q bodypr6ngs3 of the digging head shown in Figures 1 to4j andathe .acute angle .between the convergent tip surfaces s s Cited in the fileof this P 1 loosened dirt away from the centerof the cluster of r s a M9 3 that the side jets 6 will have a greater'tendg PATENTS ency to sluice such dirt than the central jet. In general, 5 593,076 vGreat;Britain ..;a... Och-8,119.47

is considerablylessthan the corresponding angle ofthe UNITEDSTATESPATENTS prongsnin Figures 1 to4. In addition, the-ridges :of the i e" 2 prongtips.are:incline drelative to a plane perpendicular 1 t 'al bg: ig'i to the axis ofthe-head sothat the ends of such ridges 50 7 e- I 19-32 closer to the heads'. axis are located farther from the 5 5 Cfeightb'n' f t g 1941. body -l than the other-'ends of such ridges. The tend- 2733 943"; is: n 1: ency 'ofthe ridges-of prongs 7, therefore, is to work'thei" 02: 42 uh 1 5 

